EUVD-2026-64314

NLTK versions before 3.9.4 contain a symlink escape vulnerability in CorpusReader.open that allows local attackers to read arbitrary files outside the corpus root. The vulnerability exists because path validation is lexical and does not account for symlink resolution, enabling attackers to place...

CVE-2026-70626

NLTK versions before 3.9.4 are affected by a symlink escape vulnerability in CorpusReader.open() . The root cause is that path validation is purely lexical and does not resolve symlinks, allowing a local attacker to place a symlink inside the corpus root to read arbitrary files outside the intend...

CVE-2026-70626

NLTK versions before 3.9.4 contain a symlink escape vulnerability in CorpusReader.open that allows local attackers to read arbitrary files outside the corpus root. The vulnerability exists because path validation is lexical and does not account for symlink resolution, enabling attackers to place...

CVE-2026-70626 NLTK before 3.9.4 Symlink Escape via CorpusReader

NLTK versions before 3.9.4 contain a symlink escape vulnerability in CorpusReader.open that allows local attackers to read arbitrary files outside the corpus root. The vulnerability exists because path validation is lexical and does not account for symlink resolution, enabling attackers to place...

CVE-2026-66393 NLTK before 3.9.4 Denial of Service via JSONTaggedDecoder

NLTK versions before 3.9.4 contain an unbounded recursion vulnerability in JSONTaggedDecoder.decodeobj that allows attackers to cause denial of service by supplying deeply nested JSON structures. Attackers can craft JSON payloads exceeding the recursion limit to trigger an unhandled RecursionErro...

CVE-2026-66393

NLTK versions before 3.9.4 contain an unbounded recursion vulnerability in JSONTaggedDecoder.decodeobj that allows attackers to cause denial of service by supplying deeply nested JSON structures. Attackers can craft JSON payloads exceeding the recursion limit to trigger an unhandled RecursionErro...

CVE-2026-66393

NLTK versions before 3.9.4 are affected by an unbounded recursion vulnerability in JSONTaggedDecoder.decode_obj() . An attacker can supply a deeply nested JSON structure that exceeds Python's recursion limit, triggering an unhandled RecursionError that crashes the process, resulting in denial of ...

EUVD-2026-64310

NLTK versions before 3.9.4 contain an unbounded recursion vulnerability in JSONTaggedDecoder.decodeobj that allows attackers to cause denial of service by supplying deeply nested JSON structures. Attackers can craft JSON payloads exceeding the recursion limit to trigger an unhandled RecursionErro...

CVE-2026-65915 NLTK before 3.10.0 Arbitrary File Read via FileSystemPathPointer

NLTK versions before 3.10.0 contain a logic bug in FileSystemPathPointer.open where the sandbox validation check compares a normalized path against itself, making the security check permanently inert. Attackers can pass file:// URLs to nltk.data.load to read arbitrary files accessible to the...

CVE-2026-65915

NLTK versions before 3.10.0 contain a logic bug in FileSystemPathPointer.open where the sandbox validation check compares a normalized path against itself, making the security check permanently inert. Attackers can pass file:// URLs to nltk.data.load to read arbitrary files accessible to the...

CVE-2026-65915

NLTK versions before 3.10.0 contain a logic bug in FileSystemPathPointer.open() where the sandbox validation check compares a normalized path against itself, rendering the security check permanently inert. An attacker with low privileges can pass file:// URLs to nltk.data.load() to read arbitrary...

EUVD-2026-64309

NLTK versions before 3.10.0 contain a logic bug in FileSystemPathPointer.open where the sandbox validation check compares a normalized path against itself, making the security check permanently inert. Attackers can pass file:// URLs to nltk.data.load to read arbitrary files accessible to the...

CVE-2026-63312

NLTK before 3.10.0 contains an arbitrary local file read vulnerability in StreamBackedCorpusView . The root cause is that the component calls builtins.open() directly instead of the sandboxed pathsec.open() , effectively bypassing the pathsec.ENFORCE security mechanism. An attacker who controls t...

CVE-2026-63312

NLTK before 3.10.0 contains an arbitrary local file read vulnerability in StreamBackedCorpusView that bypasses pathsec.ENFORCE by calling builtins.open directly instead of pathsec.open. Attackers who control the fileid argument can read arbitrary local files regardless of the ENFORCE setting,...

EUVD-2026-64333

NLTK before 3.10.0 contains an arbitrary local file read vulnerability in StreamBackedCorpusView that bypasses pathsec.ENFORCE by calling builtins.open directly instead of pathsec.open. Attackers who control the fileid argument can read arbitrary local files regardless of the ENFORCE setting,...

CVE-2026-63311

NLTK before 3.10.0 affected versions = 3.9.4 contains a server-side request forgery SSRF vulnerability in the validatenetworkurl function in nltk/pathsec.py. The resolvehostname helper catches OSError and ValueError during socket.getaddrinfo and returns an empty list; when DNS resolution fails, t...

CVE-2026-63311 NLTK before 3.10.0 SSRF via DNS Resolution Failure

NLTK before 3.10.0 affected versions = 3.9.4 contains a server-side request forgery SSRF vulnerability in the validatenetworkurl function in nltk/pathsec.py. The resolvehostname helper catches OSError and ValueError during socket.getaddrinfo and returns an empty list; when DNS resolution fails, t...

CVE-2026-63311

NLTK (Python NLP library) versions

CVE-2026-63312 NLTK StreamBackedCorpusView Bypasses pathsec.ENFORCE Arbitrary File Read

NLTK before 3.10.0 contains an arbitrary local file read vulnerability in StreamBackedCorpusView that bypasses pathsec.ENFORCE by calling builtins.open directly instead of pathsec.open. Attackers who control the fileid argument can read arbitrary local files regardless of the ENFORCE setting,...

EUVD-2026-64334

NLTK before 3.10.0 affected versions = 3.9.4 contains a server-side request forgery SSRF vulnerability in the validatenetworkurl function in nltk/pathsec.py. The resolvehostname helper catches OSError and ValueError during socket.getaddrinfo and returns an empty list; when DNS resolution fails, t...